This disclosure relates generally to polycarbonate-polysiloxane copolymer compositions and methods for their manufacture, as well as articles formed from the compositions.
Polycarbonate is a thermoplastic that is particularly suitable for use in articles employed in medical applications because of the high reliability and safety benefits resulting from its optical transparency, toughness, and heat resistance. However, one drawback of polycarbonates for certain medical applications is that they are known to adversely interact with blood as well as protein solutions. For example, when blood contacts standard polycarbonate, the number of platelets in the blood can be reduced, or when a solution containing proteins contacts polycarbonate, proteins can be deposited on the surface of the polycarbonate. A more hemocompatible polycarbonate composition comprising a polycarbonate-polysiloxane copolymer has recently been introduced, where the inclusion of the polycarbonate-polysiloxane copolymer improves the hemocompatibility of the polycarbonate. This recently introduced copolymer does not contain poly(oxyalkyl) groups as described below.
Other approaches to improving the hemocompatibility of materials such as polycarbonate have relied on the use of hemocompatible coatings applied to the surface of the article, wherein the coating includes bioactive molecules such as heparin or phosphorylcholine. Alternatively, grafting of hydrophilic polymeric moieties to the surface of the polymer has been performed. However, it is difficult to use conventional molding processes to make such surface-modified polymers without a secondary operation.
There accordingly remains a need in the market for hemocompatible and/or protein resistant polycarbonate compositions, and methods for their manufacture.